java生成二维码技术
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代码来源潭州免费视频教程
需要Qrcode_swetake.jar类库，jquery.js
后台新建EcardServlet.java,修改web.xml的servlet映射
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //处理字符编码 request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String content =request.getParameter("content"); //生成二维码 Qrcode qrcode = new Qrcode(); qrcode.setQrcodeErrorCorrect(‘M‘);//容错率L 7%,M 15%,Q 25%,H 30% qrcode.setQrcodeEncodeMode(‘B‘);//编码模式Binary qrcode.setQrcodeVersion(15);//1-40 byte[] contentBytes = content.getBytes(); int width = 235,height=235; BufferedImage image=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); //画笔 Graphics2D gsGraphics2d = image.createGraphics(); gsGraphics2d.setBackground(Color.WHITE); gsGraphics2d.setColor(Color.BLACK); gsGraphics2d.clearRect(0, 0, width, height);//绘制空白矩形 //处理二维码 int pixoff=2;//设置偏移量 boolean[][] code=qrcode.calQrcode(contentBytes); for (int i = 0; i < code.length; i++) { for (int j = 0; j < code.length; j++) { if (code[i][j]) { gsGraphics2d.fillRect(i*3+pixoff, j*3+pixoff, 3, 3);//画二维码的小方块3*3 } } } gsGraphics2d.dispose();//释放画笔资源 image.flush();//清空缓冲区，不然造成资源浪费 String fileName =UUID.randomUUID()+".jpg"; File file = new File(request.getServletContext().getRealPath("/images")+"/"+fileName); ImageIO.write(image, "JPEG", file); PrintWriter outPrintWriter = response.getWriter(); outPrintWriter.println(fileName); outPrintWriter.flush(); outPrintWriter.close(); }
前台修改index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>java 二维码扫一扫</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <style type="text/css"> *{margin:0;padding:0;} .input_btn{width:200px;height:40px;border-radius:5px;background:#d206c8;color:red;font-weight:bold;transition:all 0.5s ease;} .input_btn:hover{background:#e07185;color:fff;transition:all 0.5s ;} .ecard{float:left;} </style> </head> <body> <div class="ecarBox"> <h1>java 二维码扫一扫</h1> <br /> <p> <span>信息：</span> <input type ="text" class="input_box" id="web" placeholder="请输入有效信息..." /> <br /> <input type="button" value="生成二维码" class="input_btn" /> </p> </div> <div class="ecardOuterBox"></div> <script type="text/javascript" src="js/jquery-1.11.1.min.js"></script> <script type="text/javascript" > $(function(){ $(".input_btn").click(getEcard); }); function getEcard(){//获取二维码的方法 var web=$("#web").val(); $.ajax({ type:"post", url:"EcardServlet", data:{"content":web}, success:function(data){ $(".ecardOuterBox").empty(); $(".ecardOuterBox").append("<div class=‘ecard‘><img src=‘images/"+ data +"‘/></div>"); } }); } </script> </body> </html>
预览图片如下:
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